Among challenges likely to be facing Wren is the spotlight on the Home Office over confusion surrounding Jordanian terror suspect Abu Qatada.

David Cameron has backed Home Secretary Theresa May on the issue, following her announcement of the imminent deportation of the cleric last week, which was followed by another appeal by Qatada to the courts against the decision.

Filling the MoD role on an interim basis is the department’s head of news James Shelley, who said: ‘We’ve got some big comms challenges ahead of us in the coming months and the team and I are focused on delivering the best outcome for the department.’

News of the comms reshuffle comes after Diamond, who had worked at the Home Office since 2008, was poached from the top comms post by InterContinental Hotels Group for the role of senior vice-president global corporate affairs.

It is understood than an external recruitment process for the top MoD comms role is now taking place.

Wren, formerly a Department for Transport senior press officer, went on to become the MoD’s head of news for nine months between 2005 and 2006. He then moved to the Home Office, eventually becoming the Home Office’s acting director of comms until being replaced by Diamond.